16 實驗

baroquesoul

實驗
實驗1：
對于這個實驗你需要一個搭檔。前面步驟需要有他來完成。要準備這個實驗，遵循下面步驟：
    1、用 root 用戶登錄。
    2、用文本編輯器打開 /etc/inittab 文件。
    3、將啟動級別改為 0。
    4、保存設置。
    5、關閉計算機。將系統(tǒng)交給你的搭檔。告訴他計算機啟動進入 Linux 可能會出問題。
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    6、現(xiàn)在你的搭檔已經(jīng)設置好了你的系統(tǒng)。現(xiàn)在加電啟動進入 Linux。發(fā)生了什么事？你該如果做？
答案：
1.  
To solve this problem, you need to observe what happens when you boot this system. While not required, the first step you should take is to use the GRUB boot menu to boot into a specific runlevel. If you have any experience with Linux, you should know that an immediate shutdown after Linux goes through the boot process is associated with runlevel 0.
實驗2：
對于這個實驗需要你的搭檔設置你的系統(tǒng)
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現(xiàn)在你為你的搭檔設置系統(tǒng)，遵循下面步驟：
    1、如果你配置的 RHEL 系統(tǒng)在 VMware上，建立當前快照。如果你的搭檔沒有解決問題，這將很有用。
    2、正常啟動你搭檔的電腦。
    3、打開 /etc/fstab 文件，你會看見與 /boot 相關的行，類似下面：
    LABEL=/boot   /boot    ext3       defaults     1 2
    4、將此行加入一個排版錯誤，改動如下：
    LABEL=boot   /boot    ext3       defaults    1 2
    5、關閉計算機，告訴你的搭檔啟動系統(tǒng)。
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    6、現(xiàn)在你的搭檔已經(jīng)設置好了你的系統(tǒng)。現(xiàn)在加電啟動進入 Linux。發(fā)生了什么事？你該如果做？
答案：
2.  
In this lab, you should know almost immediately that there's a problem with the LABEL associated with the /boot directory, with an error message similar to:
fsck.ext3: Unable to resolve 'LABEL=boot'
During your exam, this may be a bit tricky. If you're very familiar with the contents of /etc/fstab, you may be able to recognize this problem right away.
Otherwise, you can verify the LABEL associated with each partition on your hard drive with the e2label command. For example, if you're checking the /dev/hda1 partition, the command would be
# e2label /dev/hda1
Some trial and error may be required, but you'll eventually see the LABEL you need in the output. For example, I see the following output from this command on my VMware-based RHEL system:
/boot
This provides the hint I need to know how to repair my /etc/fstab configuration file.
實驗3：
對于這個練習，使用測試計算機。不要使用生產(chǎn)計算機或存儲有重要數(shù)據(jù)的計算機。如果出現(xiàn)某些問題，你會無法從備份中恢復系統(tǒng)，你只有重新安裝 Linux。這個練習假設你使用 Red Hat Enterprise Linux 默認啟動加載程序， GRUB。
轉到 /boot 目錄。改變 initrd-versionnumber.img 文件名。確定名稱比較容易記，如 initrd-versionnumber.bak。重啟 Linux。當 GRUB 進入啟動序列，如果找不到 initial RAM 文件（initrd），它會停止并給出文件無法找到的消息。
現(xiàn)在你的啟動加載重新無法工作，你該怎么做？你可以進入 單用戶模式嗎？
答案：
3.  
As you practice learning about Linux for the RHCE exam, it's important to know how GRUB works. By default, it requires an initial RAM disk file, initrd-versionnumber.img. If GRUB can't find this file, it'll give you a file not found error. Since your computer does not boot, you'll need to boot with a rescue disc before you can fix the initrd file. Remember to make sure that the filename matches the name shown in /boot/grub/grub.conf exactly.
You can repeat this process with the vmlinuz file or the root directive in grub.conf. Make sure to have backups of key files so you can restore your original configuration. When you repeat this process, what happens after you select a kernel from the GRUB menu? Do you see a different error? Is it associated with a different file?
Understanding these answers can help you learn to use GRUB messages to more precisely diagnose specific problems with Linux.
實驗4：
在這個實驗中，你將創(chuàng)建一個新的 PEs 并使用他們增加 LV的大小。你所操作的 LV 用于 /var 目錄。由于你 Web 站點的需求，你的 /var 需要更多的空間提供給你的 Web 站點數(shù)據(jù)。假設你的 /etc/fstab 配置文件如下：
/dev/Volume00/LogVol00  /var   ext3   defaults  1 2
你要從 /dev/sde 和 /dev/sdf 硬件設備上添加 PEs，并添加額外的 SCSI 硬盤，/dev/sdg。假設你已經(jīng)備份了 /var 目錄下的需要數(shù)據(jù)。
答案：
4.  
If you've just added the new hard drive, you'll need to set up partitions or use the entire hard drive for PEs. Based on the premises of the lab, you have the entire SCSI /dev/sdg hard drive available, so you can just allocate this entire hard drive as PEs with the following command:
# pvcreate /dev/sdg
The next step is to extend the VG, Volume00, to include the newly configured PEs. You can do so with the following command:
# vgextend Volume00 /dev/sdg
With the additional PEs at your disposal, you can increase the size of the LV allocated to the /var directory. For example, if you wanted to increase the size to 2GB, you could run the following command:
# lvextend -L2G /dev/Volume00/LogVol00
               
               
               

本文來自ChinaUnix博客，如果查看原文請點：http://blog.chinaunix.net/u1/54648/showart_1220134.html